Mike Brown's Planets, season 4: sabbatical |
Mike Brown's Planets, season 4: sabbatical |
Oct 29 2010, 11:59 AM
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Senior Member Group: Members Posts: 3516 Joined: 4-November 05 From: North Wales Member No.: 542 |
Now on sabbatical, Mike Brown has recently reactivated his mainly Transneptunian blog. Here is a tasty two-parter on Sedna for starters: http://www.mikebrownsplanets.com/2010/10/t...ere-part-2.html
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Dec 12 2013, 05:55 PM
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Senior Member Group: Members Posts: 2530 Joined: 20-April 05 Member No.: 321 |
A hypothesis I floated a long time ago on Sedna's orbit is that it may have been shaped by a planet that was once there, but isn't anymore.
The rules of celestial billiards require that if two bodies have an orbit-altering encounter, they will leave the encounter with orbits that will cross again. But there's no rule stipulating that they will remain in those orbits. Suppose, for example, an earth-sized planet (or many) once had elliptical orbits that came close to Neptune (or another giant planet) at perihelion and ventured out towards Sedna's neighborhood at aphelion. Such planets could have tweaked Sedna's orbit, then later ceased to exist, either by being absorbed into a giant planet or being ejected from the solar system. I think there's a rich field of study ahead on how mass swarms of bodies evolve. This can involve massive computation, and has been investigated for many years, but I'm not sure how exhaustive the investigations have been. |
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Dec 12 2013, 06:30 PM
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Senior Member Group: Members Posts: 1591 Joined: 14-October 05 From: Vermont Member No.: 530 |
I think there's a rich field of study ahead on how mass swarms of bodies evolve. This can involve massive computation, and has been investigated for many years, but I'm not sure how exhaustive the investigations have been. Definitely, and most certainly not exhausted. For an idea that seems to be getting such acceptance the Nice model isn't even a decade old yet, and it came about when the ability to simulate coincided with theory. The idea of Jupiter Saturn resonance causing relative chaos, maybe that was older, but the ability to show that it could have happened and might have led to what we see today, that's still new. And if you want to make massive computation even more massive, you could add in stellar neighbors. |
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